Wrench



July 13, 1943. R. L. ARTHUR WRENCH Filed April 5, 1941 I 3nventor,$55271. Apr/w zamzr (Ittorneg Patented July 13, 1943 UNITED STATESPATENT OFFICE 6 Claims.

This invention relates to a wrench.

In the manipulation of threaded nuts, unions, pipe and tubing, it isdesirable to provide a wrench of simple construction which will grip theelement to be rotated and impart rotation thereto Without requiringadjustment or manipulation of the wrench structure, and while insuringthat the gripping jaws will not damage the surface or finish of themember embraced and engaged thereby. It is also desirable to provide awrench which will act automatically in its gripping action, such forexample as when used on parts of uniform and standard. dimensions as apart of a piece of machinery to be assembled or dismantled, orspecifically when used to tighten or loosen conduit nuts which arestandard equipment upon airplanes and the like. It is the principalobject of the present invention, therefore, to provide a wrench havingobject embracing and gripping means which act automatically whenpressure is applied to grip and rotate the object while applyin uniformand universal pressure to the object, and without possibility ofobjectionably distorting or marring the object being gripped androtated.

The present invention contemplates the provision of a wrench having ahandle adapted to be gripped at one end and being formed with a head atthe opposite end, the head supporting a rigid object embracing member,providing gripping jaws fixed with relation to each other, the

embracing member carrying yieldable gripping means acting in cooperationwith the embracing member to grip an object automatically incident tothe application of pressure to the handle.

The invention is illustrated by way of example in the accompanyingdrawing, in which:

Figure 1 is a view in side elevation showing one form of the inventionand the application to a conduit nut, and further indicating thepreliminary position of the wrench in dotted lines.

Fig. 2 is a view in plan showing the wrench.

Fig. 3 is a fragmentary view in plan showing the gripping action of thewrench as torque is applied by pressure on the handle.

Fig. 4 is a view in plan showing a modified form of the inventioncapable of use as pipe tongs or the like.

Referring more particularly to the drawing, Ill indicates a handle whichhas a grip portion I I and a head I2. The handle may be made in anydesired manner, although it is here shown as being formed with twocomplementary longitudinally separate sections I3 and I4 which may bespot welded or otherwise secured together. The head I2 comprises widenedplates I5 and I B which are formed integral with the handle sections I3and I4, respectively, and project beyond the end face I! of the handlebody. The projecting portion of the members I5 and I6 lie parallel andform an intermediate space into which a substantially crescent shapedjaw structure I8 is positioned, said jaw structure providingdiametrically opposite rigid jaw elements I9 and 20 which extend aroundone entire side of the object to be gripped and continue for a distancearound the object to be gripped beyond the transverse plane of thelongitudinal center of the object. The inner face of the jaws isrepresented by a substantially circular face portion 2| which iseccentric to the longitudinal axis of the object to be gripped. Theouter face of the jaws is represented by a partial circular face 22which is eccentric to the inner face and thus forms the jaws with aprogressively restricted outer point and a thickened central portiongiving strength to the jaw structure I8. The jaws terminate in opposedend faces 23 and 24. These faces are spaced apart a distance preferablyless than the diameter of the object to be gripped. This ischaracteristic of the preferred form of the invention since a practicaluse of the device is to grip circular nuts which are carried uponmembers of smaller diameter, the wrench being applied by first passingthe small diameter member through the throat represented by the spacebetween the jaw points 23 and 24 and thereafter moving the wrenchlongitudinally to pass over the circular nut and into an embracingposition therearound. It is of course to be understood that the wrenchmay be readily adapted for use with nuts of other outside contour, suchfor example as nuts of polygon shape. The rigid jaw structure I8 is madeout of a piece of flat stock material so that it has upper and lowerfaces 25 and 26 which fit between the opposed faces of the portions I 5and I6 of the head and will be guided thereby for a purpose to behereinafter described. The unit I8 is mounted to float in the plane ofthe handle of the wrench and to oscillate. This movement is controlledby fulcrum pins 21 and 28 which project from the faces 25 and 26 andinto slots 29 and 30. The slots 29 and 30 are substantially parallel toeach other and are formed through the plates I5 and I6 of the head I8.These slots are spaced equidistant upon opposite sides of thelongitudinal center of the wrench. The outer surface 22 of the rigid jawunit is spaced from the end face ll of the handle in order to permitlimited movement of the jaw member I8 with relation to the head.Suitable yieldable means, such as a fiat spring 3|, is interposedbetween the face ll of the handle and the surface 22 of the jawstructure 58, tending to urge the jaw structure iii to its outermostposition while the pins 2'! and 28 tend to maintain the jaw structure H3in its centrally aligned position.

As previously explained, the inner surface 2! of the jaw structure it iseccentric to the longitudinal axis of an object to be gripped. In thespace between the surface of the object and the eccentric surface 25 acrescent shaped gripping dog 32 is positioned. The back face of thisdog, as indicated at 33, is concentric with the portion of the surfaceii of the jaws. A gripping face 34 of the dog is concentric with orsubstantially conforms to the surface of the object to be gripped. Thesurface 34 is preferably serrated to increase its frictional engagementwith the object to be gripped and rotated. Intermediate the ends of thegripping jaw 32 is a pivot pin 35 which passes through the plates l5and. N5 of the head it and will permit limited oscillation of thegripping dog thereon for a purpose to be hereinafter described.

It may be desirable to provide a latch which bridges the throat betweenthe points 23 and 24 of the jaws l9 and 2B. A latch of this generalcharacter is indicated in Fig. 4 and will be hereinafter described.

Referring particularly to Fig. 4 of the drawing, it will be seen that asubstantially identical structure with the one previously described isdisclosed, save that the ends of the fixed jaws here indicated at 59 and2t terminate substantially along the median plane of the longitudinalaxis of the object to be gripped and carry latch pins $5 and 3'5. Anarcuate latch element Bil may be secured in position by these pins andW111 thus insure that in cooperation with a gripping dog 32'substantially the entire circumference of an object to be ripped will beembraced and engage-d.

In operation of the present invention the preferred form of thestructure is assembled as shown in Figs. 1 and 2 of the drawing. It willbe recognized that this invention is particularly adapted for use wherean operation is often repeated, such for example as in the assembly andmaintenance of airplanes and other machinery where parts of the samekind and dimensions must be often assembled and dissemb-led. This isparticularly true in connection with airplane work where conduit nutsmust be tightened and removed. In view of the fact that these nuts areof standard sizes the present invention contemplates that a wrenchadapted for this particular operation shall be built so that it can bequickly used without adjustment, and will make it possible for anairplane to be rapidly overhauled, which is a matter of great importancein connection with military operations.

Referring to the dotted line portions of Figs. 1 and 2, 3'3 indicates ajunction box into which a conduit all leads and upon which conduit a nutG4 is secured. As indicated in Fig. 2 of the drawing, the outsidediameter of the conduit 49 is of a size which will pass through thethroat occurring between the faces 23 and 24 of the jaws l9 and afterwhich the wrench is moved downwardly on the nut to the position shown ini so that the fixed jaws i9 and 2G and the arcuate surface it; of thegripping dog will embrace the side surface of the nut ll. It willevident that due to this arrangement it is possible to provide a maximumbearing surface contact between the jaws and the dog and the iI-I) outersurface of the nut 4 I. This eliminates the necessity for anobjectionable excessive pressure at any point between the contactingsurfaces of the wrench and the object being gripped. This has twoparticular advantages: one is that it does not mar the gripped object,and furthermore that it does not distort the object so that a suitableground connection would be obtained as in the case of the use of aconduit nut.

After the wrench has been positioned as shown in Figs. 1 and 2, pressuremay be applied to the handle in either direction, such for example as inthe direction of the arrow a shown in Fig. 3. When pressure is appliedthe handle structure swings on one of the fulcrum pins 21 or 28 and inthis particular instance the pin 21 would act as a fulcrum. As thehandle swings around this fulcrum the pin 28 will pass along slottedopening 39. The slotted openings 29 and 36 have been described as beingsubstantially parallel. It is to be understood that they are sopositioned as to be tangentially disposed to the arc described by thefulcrum pin moving therein. This will place them at a slight angle toeach other. As the handle swings on the fulcrum 21 the pivot pin willswing on he are on the fulcrum pin 2i and toward the object beinggripped. This will carry the gripping dog 32 forwardly and force itagainst the surface of the object being gripped so that the entiresurface 34 will engage the object being gripped and will act with thearcuate gripping faces 32 and 43 respectively of jaws E9 and '20 to holdthe gripped object and to permit rotation thereof. When pressure isrelieved the yieldable member will restore the fixed jaw unit H) to itsoriginal position, as shown in Fig. 2 of the drawing, and willtemporarily release the object being gripped so that the handle may beswung in a counterdirection to that indicated by the arrow a preparatoryto another gripping operation. It will be evident that due to the factthat the jaws do not have to be manipulated in any way except by thehandle, it is possible to manipulate nuts and the like at remote andinaccessible points, and it will be evident that the action of thewrench may be reversed without any adjustment but merely by a reversalof the direction of pressure as applied to the handle.

In actual practice it has been found that where conduit nuts areinvolved in the operation it has heretofore been necessary, particularlyin military operations, to discard the removed conduit nuts, due to thefact that they are often mutilated. With the present wrench, however,this material is saved, since the uniform pressure upon the nut and thecharacter of the gripping action produced does not distort the shape ofthe nut or mar its outer surface.

It is also to be pointed out that while the surfaces 34, 42 and 43 havebeen indicated as being formed in the parts themselves, that thesesurfaces might be separate elements, either serrated or formed ofremovable inserts of material having a high coefiicient of friction,such for example as Bakelite.

Attention is directed to the fact that in Fig. 4 of the drawing pivotpin 35' is carried by the gripping dog 32 and extends through a slottedopening 45. This opening extends transversely of the longitudinal axisof the wrench and will permit lateral adjustment of the gripping dog 32with relation to the object gripped. It is to be understood that thisconstruction might be employed in the form of the invention shown inFig. 2 if desired.

While I have shown the preferred form of my invention as now known tome, it will be understood that various changes may be made incombination, construction and arrangement of parts by those skilled inthe art, without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A wrench, comprising a rigid handle, object embracing means includinga pair of rigid jaws having a laterally open throat and embracing morethan one-half of the circumference of an object to be gripped, said jawsengaging the object near the ends of the jaws, means articulatelymounting said embracing means at one end of the handle for movement inthe normal pressure plane of the wrench, a gripping dog disposed between said jaws and centrally pivoted upon a fixed pivot on the handle,whereby relative movement between the handle and the embracing memberwill force the gripping dog toward the object being gripped and willcooperate with the gripping ends of the fixed jaws in gripping androtating the same and yieldable means tending to hold the parts in anon-gripping position.

2. A wrench, comprising a rigid handle structure including a grippingportion and a head, a rigid embracing unit including two arcuate jawshaving a laterally open throat between their ends and being disposed infixed relation to each other for encompassing more than one-half of thecircumference of an object to be gripped and engaging the object nearthe ends of the jaws, means articulately connecting said rigid embracingmember to the head of the handle while supporting the embracing memberin the normal plane of pressure of the wrench and permitting oscillatingmovement of the embracing means in said plane, an arcuate gripping dogdisposed between the fixed jaws and within the confines of the embracingmeans, a fixed central pivot mounting said gripping jaw upon the head ofthe handle and whereby pressure applied to the handle in an operatingplane will tend to swing the handle with relation to the embracingmember and force the gripping dog toward the object embraced by thefixed jaws, whereby to grip and rotate the object.

3. A wrench, comprising a handle including a gripping portion and a headat one end thereof, a rigid embracing unit formed with fixed spaced jawsadapted to encompass an object to be gripped for a distance greater thanone-half of its circumference, fixed pins carried by said rigid memberand disposed in equal spaced relation to the longitudinal median line ofthe handle, slotted seats in the head of the handle to receive saidpins, whereby the handle may swing with relation to the embracing memberusing either of said pins as a fulcrum, yieldable means tending to holdthe embracing member in its normal central position, an arcuate grippingdog encompassed by said embracing member and disposed between the jawsthereof, and a fixed pivotal mounting for said dog on the head of thehandle, whereby relative movement of the head of the handle with theembracing means will force the gripping dog against an object tobegripped and will cooperate with the fixed jaws to grip and rotate thesame as pressure is applied to the handle.

4. A wrench, comprising a handle including a gripping portion and a headat one end thereof, a rigid embracing unit formed with fixed spaced jawsadapted to encompass an object to be gripped for a distance greater thanone-half of its circumference, fixed pins carried by said rigid memberand disposed in equal spaced relation to the longitudinal median line ofthe handle, slotted seats in the head of the handle to receive saidpins, whereby the handle may swing with relation to the embracing memberusing either of said pins as a fulcrum, yieldable means tending to holdthe embracing member in its normal central position, an arcuate grippingdog encompassed by said embracing member and disposed between the jawsthereof, and a fixed pivotal mounting for said dog on the head of thehandle, whereby relative movement of the head of the handle with theembracing means will force the gripping dog against an object to begripped and will cooperate with the fixed jaws to grip and rotate thesame as pressure is applied to the handle, said fixed jaws beingcharacterized as forming an entry throat of less width than the outsidedimensions of the object to be gripped.

5. A wrench, comprising a handle structure having a gripping portion anda head at one end thereof, an embracing element for an object to begripped, said embracing element including a pair of jaws fixed withrelation to each other and forming a throat at their outer terminatingends of a width less than the diameter of an object to be gripped, theinner surface of the jaws describing a portion of a circle, a pair offulcrum pins carried by the jaws, one disposed at each side of thelongitudinal center line of the wrench, guideways in the head of thewrench and at the outer ends of which said pins normally seat, wherebypressure applied to the wrench handle in the plane of the embracingmember will cause the handle to fulcrum in the end of one of saidguideways and the other guideway to move along its fulcrum pin, and anarcuate dog disposed between the fixed jaws and pivotally mounted to thehead along the plane of the longitudinal axis of the wrench, whereby asthe wrench handle swings upon one of its fulcrum pins the arcuate dogwill move against an object being gripped and will cooperate with thefixed jaws to grip and rotate the same.

6. A wrench, comprising a rigid handle, object embracing means includinga pair of rigid jaws the outer ends of which are spaced apart to form athroat, said jaws embracing more than onehalf of the object, meansarticulately mounting said embracing means at one end of the handle formovement in the normal pressure plane of the wrench, a gripping dogdisposed between said jaws and centrally mounted upon a fixed pivot onthe handle, whereby relative movement between the handle and theembracing member will force the gripping dog toward the object beinggripped and will cooperate with the fixed jaws in gripping and rotatingthe same, the pivotal connection between the arcuate dog and the headbeing a pin carried by the dog and extending into a laterally disposedelongated seat in the head.

ROBERT L. ARTHUR.

